Update a TODO in dartdoc.dart (#121620)

Update a TODO in dartdoc.dart

Author: goderbauer

dev/tools/dartdoc.dart

@@ -143,11 +143,12 @@ Future<void> main(List<String> arguments) async {
 
   // Dartdoc warnings and errors in these packages are considered fatal.
   // All packages owned by flutter should be in the list.
-  // TODO(goderbauer): Figure out how to add 'dart:ui'.
   final List<String> flutterPackages = <String>[
     kDummyPackageName,
     kPlatformIntegrationPackageName,
     ...findPackageNames(),
+    // TODO(goderbauer): Figure out how to only include `dart:ui` of `sky_engine` below, https://github.com/dart-lang/dartdoc/issues/2278.
+    // 'sky_engine',
   ];
 
   // Generate the documentation.